“He opened the door and they said ‘kneel down’ and they put a gun to his head and they said, ‘Where are the three boys?’

“And he said, ‘I don’t know. And if I knew, I wouldn’t tell you’.

“And they said, ‘Are you Sinn Fein?’ and he said, ‘Born and I’ll die’ and they said, ‘Then die’.

“And they shot him three times – once in the head, once in the chest and once in the stomach.

“And then they shot my father and left him for dead.”

Speaking at the launch of the series, director Mary Cranitch told the Irish Sunday Mirror : “Brendan O’Carroll is great in Mrs Brown’s Boys so to have him on board for Who Do You Think You Are? is brilliant.

“His episode is about the Irish War of Independence in 1920 and the murder of his grandfather and what really happened to him.

“I couldn’t imagine if you made a standard history documentary about the Irish War of Independence that it would be colossal with viewers.

“But with the combination of Who Do You Think You Are? and Brendan O’Carroll, then I am sure it means it will get many millions of viewers.”